Mercurial > dropbear
view gensignkey.c @ 1659:d32bcb5c557d
Add Ed25519 support (#91)
* Add support for Ed25519 as a public key type
Ed25519 is a elliptic curve signature scheme that offers
better security than ECDSA and DSA and good performance. It may be
used for both user and host keys.
OpenSSH key import and fuzzer are not supported yet.
Initially inspired by Peter Szabo.
* Add curve25519 and ed25519 fuzzers
* Add import and export of Ed25519 keys
author | Vladislav Grishenko <themiron@users.noreply.github.com> |
---|---|
date | Wed, 11 Mar 2020 21:09:45 +0500 |
parents | 7402218141d4 |
children | c795520269f9 |
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#include "includes.h" #include "dbutil.h" #include "buffer.h" #include "ecdsa.h" #include "genrsa.h" #include "gendss.h" #include "gened25519.h" #include "signkey.h" #include "dbrandom.h" /* Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */ static int buf_writefile(buffer * buf, const char * filename) { int ret = DROPBEAR_FAILURE; int fd = -1; fd = open(filename, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR); if (fd < 0) { dropbear_log(LOG_ERR, "Couldn't create new file %s: %s", filename, strerror(errno)); goto out; } /* write the file now */ while (buf->pos != buf->len) { int len = write(fd, buf_getptr(buf, buf->len - buf->pos), buf->len - buf->pos); if (len == -1 && errno == EINTR) { continue; } if (len <= 0) { dropbear_log(LOG_ERR, "Failed writing file %s: %s", filename, strerror(errno)); goto out; } buf_incrpos(buf, len); } ret = DROPBEAR_SUCCESS; out: if (fd >= 0) { if (fsync(fd) != 0) { dropbear_log(LOG_ERR, "fsync of %s failed: %s", filename, strerror(errno)); } m_close(fd); } return ret; } /* returns 0 on failure */ static int get_default_bits(enum signkey_type keytype) { switch (keytype) { #if DROPBEAR_RSA case DROPBEAR_SIGNKEY_RSA: return DROPBEAR_DEFAULT_RSA_SIZE; #endif #if DROPBEAR_DSS case DROPBEAR_SIGNKEY_DSS: /* DSS for SSH only defines 1024 bits */ return 1024; #endif #if DROPBEAR_ECDSA case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: return ECDSA_DEFAULT_SIZE; case DROPBEAR_SIGNKEY_ECDSA_NISTP521: return 521; case DROPBEAR_SIGNKEY_ECDSA_NISTP384: return 384; case DROPBEAR_SIGNKEY_ECDSA_NISTP256: return 256; #endif #if DROPBEAR_ED25519 case DROPBEAR_SIGNKEY_ED25519: return 256; #endif default: return 0; } } int signkey_generate_get_bits(enum signkey_type keytype, int bits) { if (bits == 0) { bits = get_default_bits(keytype); } return bits; } /* if skip_exist is set it will silently return if the key file exists */ int signkey_generate(enum signkey_type keytype, int bits, const char* filename, int skip_exist) { sign_key * key = NULL; buffer *buf = NULL; char *fn_temp = NULL; int ret = DROPBEAR_FAILURE; bits = signkey_generate_get_bits(keytype, bits); /* now we can generate the key */ key = new_sign_key(); seedrandom(); switch(keytype) { #if DROPBEAR_RSA case DROPBEAR_SIGNKEY_RSA: key->rsakey = gen_rsa_priv_key(bits); break; #endif #if DROPBEAR_DSS case DROPBEAR_SIGNKEY_DSS: key->dsskey = gen_dss_priv_key(bits); break; #endif #if DROPBEAR_ECDSA case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: case DROPBEAR_SIGNKEY_ECDSA_NISTP521: case DROPBEAR_SIGNKEY_ECDSA_NISTP384: case DROPBEAR_SIGNKEY_ECDSA_NISTP256: { ecc_key *ecckey = gen_ecdsa_priv_key(bits); keytype = ecdsa_signkey_type(ecckey); *signkey_key_ptr(key, keytype) = ecckey; } break; #endif #if DROPBEAR_ED25519 case DROPBEAR_SIGNKEY_ED25519: key->ed25519key = gen_ed25519_priv_key(bits); break; #endif default: dropbear_exit("Internal error"); } seedrandom(); buf = buf_new(MAX_PRIVKEY_SIZE); buf_put_priv_key(buf, key, keytype); sign_key_free(key); key = NULL; buf_setpos(buf, 0); fn_temp = m_malloc(strlen(filename) + 30); snprintf(fn_temp, strlen(filename)+30, "%s.tmp%d", filename, getpid()); ret = buf_writefile(buf, fn_temp); if (ret == DROPBEAR_FAILURE) { goto out; } if (link(fn_temp, filename) < 0) { /* If generating keys on connection (skipexist) it's OK to get EEXIST - we probably just lost a race with another connection to generate the key */ if (!(skip_exist && errno == EEXIST)) { dropbear_log(LOG_ERR, "Failed moving key file to %s: %s", filename, strerror(errno)); /* XXX fallback to non-atomic copy for some filesystems? */ ret = DROPBEAR_FAILURE; goto out; } } /* ensure directory update is flushed to disk, otherwise we can end up with zero-byte hostkey files if the power goes off */ fsync_parent_dir(filename); out: if (buf) { buf_burn(buf); buf_free(buf); } if (fn_temp) { unlink(fn_temp); m_free(fn_temp); } return ret; }